Siemens SIMATIC S7-1500 System Manual page 515

Glossary
Safety class
Safety level (Safety Integrity Level) SIL according to IEC 61508. The greater the Safety
Integrity Level, the stronger the measures for preventing system errors as well as for control
of system errors and hardware failures.
With the fail-safe modules, use up to safety class SIL3 is possible.
Safety function
Mechanism integrated in F-CPU and F-I/O that enables use in the SIMATIC Safety fail-safe
system.
According to IEC 61508: Function that is implemented by a safety relay to keep the system in
the safe state in case of a specific error or to bring it into a safe state.
Safety program
Safety-related user program
SELV
Safety Extra Low Voltage = Safety extra-low voltage
SNMP
SNMP (Simple Network Management Protocol) is the standardized protocol for performing
diagnostics on and assigning parameters to the Ethernet network infrastructure.
In the office setting and in automation engineering, devices from a wide range of vendors on
the Ethernet support SNMP.
You can operate SNMP-based applications on the same network in parallel to applications
with PROFINET.
The scope of supported functions varies depending on the device type. For example, a switch
has more functions than a CP 1616.
Switch
PROFIBUS is a linear network. The communications nodes are linked by means of a passive
cable - the bus.
By contrast, Industrial Ethernet consists of point-to-point connections: Each communications
node is directly connected to exactly one other communications node.
If you want to link a communications node to multiple communications nodes, you connect
this communications node to the port of an active network component (the switch). You can
connect other communications nodes (including switches) to the other ports of the switch.
The connection between a communications node and the switch remains a point-to-point
connection.
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S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF